Involvement of Ca super(2) super(+) in globular adiponectin-induced reactive oxygen species

• Published in: Biochemical and biophysical research communications Vol. 381; no. 4; pp. 649 - 653
• Main Authors: Akifusa, S, Kamio, N, Shimazaki, Y, Yamaguchi, N, Yamashita, Y
• Format: Journal Article
• Language: English
• Published: 17-04-2009
• ISSN: 0006-291X
• DOI: 10.1016/j.bbrc.2009.02.115

Globular adiponectin (gAd) induces the generation of reactive oxygen species (ROS) and nitric oxide (NO) in the murine macrophage cell line RAW 264. We investigated the role of Ca super(2) super(+) in gAd-induced ROS and NO generation. Pretreatment with BAPTA-AM, a selective chelator of intracellular Ca super(2) super(+) ([Ca super(2) super(+)] sub(i)), partially reduced gAd-induced generation of ROS and NO in gAd-treated RAW 264 cells. The lowest [Ca super(2) super(+)] sub(i) occurred 30min after gAd treatment, after which [Ca super(2) super(+)] sub(i) increased continually and exceeded the initial level. The mitochondrial Ca super(2) super(+) ([Ca super(2) super(+)] sub(m)) detected by Rhod-2 fluorescence started to increase at 6h after gAd treatment. Pretreatment with a NAD(P)H oxidase inhibitor, diphenyleneiodonium, prevented the reduction of [Ca super(2) super(+)] sub(i) in the early phase after gAd treatment. Calcium depletion by BAPTA-AM had no effect on the gAd-induced [Ca super(2) super(+)] sub(m) oscillation. The administration of a specific calmodulin inhibitor, calmidazolium, significantly suppressed gAd-induced ROS and NO generation and NOS activity.